Some host factors and environmental conditions may modify the effects of methanol, paraquat and aspartame. Methanol is a hazard to children when it is applied as a body rub for fever or to relieve colic; when accidentally used in formula instead of water; or when abused by older children and adolescents for inebriation or sedation. Inhalation of solvent vapors containing methanol and methylene chloride caused fatal poisoning in an adult. Methanol is absorbed through skin about three times as fast when mixed with gasoline or diesel fuel. Paraquat is more toxic to experimental animals when co-administered with many other chemicals. There are reports of human fatalities from paraquat in field work after heavy exposure of the skin (or broken skin); spraying in confined locations; or by unclogging sprayguns by sucking or blowing. Helicopter spraying of illicit Cannabis may be hazardous if persons on the ground are not warned; if they brush against wet foliage; or if interspersed or nearby food crops are eaten. There are reports of paraquat effects on DNA and mutagenicity. Aspartame may be hazardous to phenylketonuric individuals, very young infants, and patients with severe liver impairment. A diketopiperazine-type conversion product is more toxic in animals than is aspartame. Formation of the product is faster at increased temperature, moisture, acidity or alkalinity, and some aspartame preparations have designated shelf lives of about half-a-year. Other Activities: Clinical and epidemiological llterature cannot be evaluated if the sex of subjects is not clearly defined. A case for clarification in medical, scientific and technical literature has been made. Data from the National Toxicology Program are being evaluated for the relationship between structure and toxicity.